It is well known for creams, gels and other similarly viscous substances to be sold in small, typically cup-shaped, containers with a protective cover. In order to use the substance contained in such a container, a user removes the cover and by dipping his finger into the substance may remove a small amount thereof. Particularly in the area of cosmetics and substances having medical applications, it is desirable to keep the substance in the container in an uncontaminated state.
This is, however, not achieved with containers such as those described above, as the finger of a user is unlikely to be totally germ free and by dipping his finger into the substance in the container, the user causes the substance to become contaminated.
Disclosed in U.S. Pat. No. 3,128,923 and French Patent No. 1,377,658, both to Gabler, are containers for receiving and delivering pasty substances, each container comprising a jar-shaped container having a cover, an inverted cup placed within the container and being attached thereto by means of a cylindrical sleeve. The inverted cup defines an extrusion aperture in a base portion thereof and a screw thread on an inward-facing surface thereof. There is also provided a disk-like element threadably mounted within the inverted cup parallel to the base portion and defining, together with a portion of the inverted cup, a storage volume for the pasty substance. The disk-like element is pressed towards the base portion of the cup by a spring provided between the disk-like element and the container. The height of the spring is unrelated to the height of the container.
Among disadvantages inherent in the Patents to Gabler are that the containers disclosed have relatively complex structures. This is exemplified by the disk-like element and the spring being discrete members, rather than a single integral member.
Disclosed in U.S. Pat. No. 1,642,108 to Geake is a Dispensing Container comprising a cylindrical container having an open end, a rotatable cap member defining an extrusion orifice and mounted onto the open end of the container, a helical member placed within the container and extending axially therewithin, the helical member being fixed at one end to the cap member while being in rotational contact with a closed end of the container, there also being provided a disk-shaped piston member made of cork, located between the open and closed ends of the container and oriented parallel to the cap member and mounted onto the helical member.
As the cap member is rotated in a predetermined sense the piston member is driven along the helical member towards the cap member, thus causing a substance contained between the piston member and the cap member to be extruded through the orifice.
A particular disadvantage of the container to Geake is that although there are also disclosed pin members for reinforcing the piston member and for ensuring stability between the piston member and the helical member, after a relatively short period of time the piston member may suffer from wear, not only at its connection location with the helical member, but also at a contact edge between the piston member and the container. Moreover, no protective cover is provided to prevent contamination of a substance within the container.
Disclosed in U.S. Pat. No. 3,059,820, also to Gabler, is a Box for Holding and Delivering Pasty Substances comprising a shallow cylindrical container with a slip-on lid, a disk-like cover portion mounted within the container and defining an orifice, a piston threadably mounted within the container and parallel to the cover portion and a leaf spring, located between and fixed to a rotatable bottom portion of the container and the piston, the spring exerting a force on the piston in the direction of the cover portion. A pasty substance is contained between the piston and the cover portion. As the bottom portion is rotated in a predetermined direction, the spring and the cover portion are rotated accordingly and the pasty substance is extruded through the orifice.
A particular disadvantage of the box to Gabler is that due to the use of a leaf spring, the full depth of the container cannot be used for storage of the pasty substance. In addition, the box has a relatively complex structure.
Disclosed in U.S. Pat. No. 4,139,127 to Gentile is a Plunger-Type Dispenser with a Ratchet Actuator. The dispenser comprises a cylindrical reservoir for a viscous material to be dispensed, a rotatable cover defining apertures, a centrally-located screw extending between the rotatable cover to which it is fixed and a bottom surface of the reservoir and a plunger oriented parallel to the rotatable cover and mounted onto the screw, the viscous material being retained between the plunger and the rotatable cover.
As the cover is rotated in a predetermined sense, the screw is rotated correspondingly such that the plunger moves along the screw towards the cover, thereby causing extrusion of the viscous material. There is also provided a protective lid for the container.
A disadvantage of the Dispenser to Gentile is that, due to the presence of the centrally-located screw, the dispenser may not be filled by conventional apparatus but it instead requires specialized equipment for filling.